This project will develop a new prosthetic ankle-foot system that allows Women Veterans to more easily change between their footwear of choice, including high heel shoes, allowing Women Veterans to more fully reintegrate into their lives after amputation. The proposed system will also be useful for Women and Men Veterans who would like to more easily switch between footwear of different heel heights for sports and other activities (e.g., cowboy boots and athletic shoes). Lastly, the proposed work will be relevant to many of the nearly 2 million Americans living with limb loss (Ziegler-Graham et al, 2008), with future versions of customized feet potentially being highly relevant for children with amputations. The vast majority of prosthetic feet are aligned for a specific heel height shoe, with a potentially de-stabilizing effect on gait if the user decides to wear footwear with different heel heights. Although there are a small number of ?heel-height adjustable? feet on the market, the shapes of the plantar surfaces of these feet do not change to match the interior of different footwear, restricting the range of shoes that can be used without instability of the foot within the shoe. Additionally, alignment changes for different footwear are performed by the user rather than by a certified prosthetist, increasing the likelihood of sub-optimal alignment. Lastly, there are no commercially available prosthetic feet that can adjust to shoes of different widths, further limiting footwear options. In order to maximize the participation and functional mobility of Women and Men Veterans with leg amputations, there is a great need for the development of a prosthetic foot/ankle system that could accommodate a diverse range of footwear and could be changed easily and quickly by the user while retaining the clinically optimal alignment determined by the prosthetist. The purpose of this project is to develop a new ankle-foot prosthesis system that will allow Veterans with amputations to choose any footwear with heel heights between 0-100mm (0-4 inches), and to be able to easily switch between these footwear without needing to change the alignment of their prosthesis. Prosthetic ankle-foot systems will also be developed to cover a range of sizes between 22 and 28 cm (women?s sizes 4.5-13.5 or men?s sizes 3-12). Mechanical testing using the ISO 10328 standard will be used to determine structural strength and durability of the ankle-foot system. The ISO 10328 standard includes static proof, ultimate strength, and durability testing to 2 million cycles. Failures during mechanical testing will inform changes in the design, followed by repeated mechanical testing. A durability testing threshold of 300,000 cycles will be used to suggest sufficient durability for a one month take home test (safety factor > 3). Six Veterans with leg amputations (N=3 women and N=3 men) will participate throughout the development project, providing feedback to improve the design and comparing the novel system to the Elation, a commercially-available adjustable heel-height foot. At the end of the project, a subset of these Veterans will take the system home for one month, each using three pairs of shoes with different heel heights of their choice. During the one month testing, Veterans will be contacted weekly to obtain feedback from real-world usage, which will be used to improve the design. Technology transfer efforts will begin during this project, including travel to conferences attended by prosthetics companies. Dissemination is also planned during the second half of the project.